Mist trapping shield for lens surfacing machines



H. w. KbsBAB Dec. 18, 1951 MIST TRAPPING SHIELD FOR LENS SURFACINGMACHINES Filed July 22, 1949 llll l llllll'l I I2 INVENTOR. BY HAROLD W.KOSBAB Patented Dec. 18, 1951 MIST TRAPPING SHIELD FOR LENS SURFACINGMACHINES Harold W. Kosbab, Ironequoit, N. Y., assignor to Bausch & LombOptical Company, Rochester, N. Y., a corporation of New York ApplicationJuly 22, 1949, Serial No. 106,248

2 Claims.

This invention relates to improvements in high speed surfacing machinessuch as lens grinders and polishers and the like and relates moreparticularly to means for trapping the mist or atomized liquid abradantthat is produced when the liquid strikes the rapidly rotating tool.

When using diamond charged tools for lens grinding, the tool spindlesare rotated at relatively high speeds of about 3000-4000 R. P. M. Thetools are carried at the upper ends of vertical spindles and a liquidcoolant is supplied to the surface of the tool as the lens is held ingrinding contact therewith. Since the tool is rotating at a high speed,the liquid is thrown off the periphery of the tool by centrifugal forceand is atomized. The atomized particles form a mist or fog that rises upand wets the arms and body of the operator as well as the overhangingparts of the machine.

It is, therefore, an object of this invention to provide novel means fortrapping the mist that is produced as the liquid coolant is thrown offthe tool and against the side of the splash pan in surfacing machines ofthe high speed type.

It is a further object to provide such a device which is efficient inoperation, does not limit the usefulness of the surfacing machine, andaffords easy demountability of the surfacing tool without disturbing themist trapping means.

A further object is to provide a mist trapping shield for a high speedsurfacing machine which is self-locating, easily demountable from themachine without the use of tools and which expedites the cleaning of thesplash pan.

Further objects and advantages will be apparent from the novel detailsof construction and combination of parts as described hereinafter andshown on the accompanying drawing in which:

Fig. 1 is a substantially vertical sectional view of a lens surfacingmachine embodying one form of my invention,

Fig. 2 is a perspective view of a section of the mist trapping shieldshown in Fig. l, and

Fig. 3 is a fragmentary sectional view of a modified mist trappingshield.

A lens Surfacing machine is shown generally at in in Fig. 1 having astationary splash pan H, the bottom of which is in the form of areservoir Ii for receiving a coolant liquid i2. The pan H rests on astand of suitable design or may be atr tached to a machine base, notshown, which houses mechanism, such as a motor, coolant pump, or otherauxiliary apparatus required by the surfacing operation. Through acentral opening I3 in the bottom of the pan I I there projects 2 a highspeed spindle M, the lower end of which is connected to suitable motivepower such as an electric motor, not shown. On the upper end of thespindle M, a surfacing tool I5 is demountably secured by any suitablemeans such as the tapered, frictional connection I6. A jet of liquidcoolant 20 is supplied to the tool I5 by means of a nozzle I! which isconnected by a valve l8 and a supply pipe l9 to a suitable coolant pumpor gravity tank connected with the reservoir ll so as to provide acirculating system such as is well known in the art.

A lens blank is shown at 2| in operating position on the tool I5, theblank being secured by a suitable adhesive pitch on a lens block 22. The

lens blank 2| is held against the tool I5 by a pressure pin 23 having apointed end which is seated in a conical recess 24 in the back of thelens block 22. Pressure is manually transmitted to the pressure pin 23by the operator through a swivelled operating lever 25 connected by africtional lock 26 to a head 21 through which the pin 23 projects.

According to this invention, a mist trapping shield 28 is providedinside the pan l I to prevent the atomized liquid or mist, which isproduced when the coolant I2 is centrifugally thrown oil the tool 15against the side of the pan l I, from rising out of the pan and onto theoperator or parts of the machine. The shield 28 is preferably built inthe form of a flat annular plate which is inclined somewhat towards thecenter. A central circular opening 29, provided in the shield 28, shouldbe large enough to permit easy removal of the tool l5 therethrough. Theopening 29 should also be large enough to allow ample operatingclearance between the pressure pin 23 and the shield 28 when the pin isswung to extreme sideward position when grinding a strong curvature onthe lens as shown in Fig. 1. Moreover, the diameter of the opening 29must be controlled within limits to provide a maximum effectiveness ofmist suppression while at the same time obtainin the above-mentionedclearance requirements.

It has been found that the diameter of the opening 29 may vary fromabout 8-12 inches and that the edge of the opening 29 should be about 13inches above the tool i'5. In one successful embodiment of the inventionthe splash pan I I is about 10 inches deep and has an inside diameter ofabout 17 inches while the shield opening 29 has a diameter of about 10inches and the edge of the opening 29 is located about 1% inches abovethe tool l5. It is to be understood that these dimensions are notcritical and that they need only be such as to afford easy access to thetool and allow ample operating clearance for the pressure pin 23 whilestill permitting proper functioning of the mist trapping shield.

For convenience in assembling the shield 28 in splash pans havinginturned lips at the top, the shield, as shown in Fig. 2, may be made inabutting sections 3% of any desired angular extent which closely lit theinterior of the pan ll when assembled together to form the shield. Itwill be understood that when all the sections 34 have been set into thepan, they position each other correctly and brace each other againstdis,- placement. If necessary, recesses 35 may be formed in theadjoining edges of the shield sec tions 34 so as to clear obstructionssuch as the supply pipe 19.

As shown in Fig. 1, means are provided for holding the shield 28 in aposition above the tool 15,, this .means comprising a plurality ofbafile plates 3i which serve the double purpose of supporting the shield28 and also reducing the swirling velocity of the mist in the pan.Bafile plates 3! are preferably attached to the shield 28 by screws 32projecting through holes in the baffle plate extensions 33 underneaththe shield. Although bafiie plates 31 are shown in radial position,other positions, such as tangential, spiral, or otherwise, are effectivefor the purpose ofthis invention so long as the baflles extend acrossthe surface of the shield 28 and stand substantially vertically in thepan I i. Assembly of the shield is very simply accomplished without .theuse of tools by merely setting the individual sections 36 into place inthe pan H in abutting relation to each other whereupon satisfactoryproper alignment and security of each of such sections is automaticallysecured.

With reference to the modification of my invention shown in Fig. 3, ainistshield ifi is provided in a form of an annular plate similar tothat shown in Fig. 1 but shield 49 is held in position above thesurfacing tool b different means. The shield 6 may be constructed as anintegral member or may be made in sections of any desirable shape andsize for convenience in assembling this device in splash pans havinginturned lips around the upper edge. The supporting means for the shield4t, here shown, consists of a plurality of hooks ii reaching over thetop edge of a splash pan 42 and these hooks are attached to the shieldin any suitable manner such as by rivets 6'3. Alternatively, the shield49 may be positioned in the pan 42 by other means i than the hooks M,such means being, for instance, a plurality of inwardly projecting studsor shoulders secured to the inside of the pan and bearingagainst theunder side of the shield. Baffle plates M are attached to the under sideof shield ii] by means of rivets or screws 45.

Assembly of this form of the invention is accomplished by simplyinserting the shield 49 in position in the pan 42 and placing the hooksover the upper edge of the pan. In case the shield 40 is composed ofsections, each successive section is hooked progressively onto the lipof the pan as the section is lowered into the pan until the shield 49 iscompletely assembled. As in the first embodiment of the invention, eachof such sections is positioned and braced by its neighboring section.

From. the foregoing, it. will be seen that I have provided a simple andeflicient shield for preventing mist from rising out of the splash pansof surfacing machines, said shields being selflocating and capable ofbeing assembled in operating position without the use of tools, all ofwhich is in accordance with the stated objects of this invention.Although but certain embodiments have been shown and described indetail, it will be understood that these embodiments are not exclusiveand changes may be made in the form and arrangement of the parts andsubstitutions may be made therein without departing from the spirit oftheinvention as defined in the appended claims.

,I claim:

1. A lens grinding machine comprising a vertical, rotatable spindle, asurfacing tool on the upper end of the spindle, a splash pan surroundingthe tool, means for supplying a liquid to the tool, means for rotatingthe spindle at a high speed so that some of the liquid which strikes thetool is atomized, a substantially annular shield horizontally positionedwithin the pan above the tool for trapping the atomized liquidparticles, the central opening in the shield affording access to thetool, and radially disposed spaced baffle plates extending downwardlyfrom the under side of the shield whereby the atomized liquid is trappedand prevented from rising above the shield. V

2. In a machine for surfacing lenses and the like having a stationarysplash pan surrounding a rapidly rotating tool which is supplied with ajet of liquid coolant, the combination of an annular mist catchingshield located contiguous to the inside of the pan in a position higherthan that of said tool, said shield being a flat ring constructed inadjoining removable sections, and at least one downwardly extendingbaffle attached transversely across each of said sections, each baffieresting at its lower edge on the bottom of the pan for the dual purposeof supporting the shield and reducing the swirling velocity of the mistso as to prevent it from rising out of the pan.

HAROLD W. KOSBAB.

REFERENCES CITED Ihe following references are of record in the file ofthis patent:

UNITED STATES PATENTS

